The present invention relates to an apparatus and a method for supporting a document data search. In particular, the present invention relates to an apparatus and a method for supporting a document data search based on a keyword.
Use of a search engine has become the mainstream of search methods for searching the Internet for desired information, for example. As the World Wide Web (WWW) grows larger and larger, the number of web pages displayed as the search results becomes larger as well. Accordingly, it is not always true that the information actually needed by the user is displayed at the top of the search results.
Users need to consider a search word from various perspectives as an input to the search engine. For example, users need to consider whether or not a particular search word is actually the appropriate one, what search word is appropriate to narrow down the search results into ones that include only desired information, approximately how many search words are appropriate, or the like. As described above, it is difficult for average users to determine what search word is appropriate as the input to a search engine.
In this respect, a technique for automatically generating a search query including a combination of search words has been proposed heretofore (refer to Koji Eguchi and two others, “Incremental Query Expansion Considering Adaptation to User's Behavior Based on Clustering the Search Results,” Research Report of Information Processing Society of Japan, 98-DBS-114, Vol. 98, No. 2, Information Processing Society of Japan, pp. 43-48, Jan. 19, 1998 (hereinafter, referred to as Non-Patent Document 1), and Hideki Mima and another, “Development of Web Information Search Support System for Children,” Feb. 14, 2004, INFORMATION-TECHNOLOGY PROMOTION AGENCY, JAPAN (on line), Internet URL: http://www.ipa.go.jp/SPC/report/03fy-pro/mito/15-1198d.pdf (search date, Apr. 10, 2008) (hereinafter, referred to as Non-Patent Document 2), for example). According to the technique disclosed in Non-Patent Document 1, a huge amount of search results are grouped into clusters, and then, the query is gradually modified each time a user confirms a cluster as an appropriate one. In the technique disclosed in Non-Patent Document 2, search path information is generated by use of ontology information or the like and then presented to the user. The query is then expanded when the user selects a search path.
In addition, the following shows other techniques for supporting a search. For example, disclosed is a technique for searching multiple information sources (refer to Japanese Patent Application Publication No. 2000-250935 (hereinafter referred to as Patent Document 1), for example). In this technique, locations of information and classification information are managed by use of a classification tree, and then, information including a search item and a search condition for finding the structure of the classification tree and an information source are managed as a class definition. Then, a search is performed on the multiple information sources by tracking back entry information stored in the classification tree of the information. In addition, disclosed is a technique for automatically displaying information indicating what hit rate can be obtained as a result of search on a set of original search results by using a new search condition, or the like (refer to Kazuhiro Hayakawa and two others, “A Visual User Interface for Refining Search Engine Results,” Research Report of Information Processing Society of Japan, 98-HI-76, 98-IM-33, Vol. 98, No. 9, Information Processing Society of Japan, pp. 25-30, Jan. 29, 1998 (hereinafter, referred to as Non-Patent Document 3), for example). Moreover, disclosed is a technique for visually arranging and displaying web contents in search results with their web-specific link relationships by use of characteristic information given to the search results (refer to Kobayasi Aki, “User Interface for Search in Web Link Space,” 2003, Telecommunications Advancement Foundation (on line), Internet URL: http://www.taf.or.jp/publication/kjosei—20/pdf/p453.pdf (search date, Apr. 1, 2008) (hereinafter, referred to as Non-Patent Document 4), for example). In addition, there is another technique for displaying a spring graph including search word candidates as nodes and co-occurrence relationships between the search word candidates as the edges (refer to Nagahata Hiroomi and another, “Query Suggestion Using Plural Visualization Techniques,” Mar. 10, 2008, Institute of Electronics, Information and Communication Engineers (on line), Internet URL: http://www.ieice.org/˜de/DEWS/DEWS2008/proceedings/files/b5/b5-5.pdf (search date Apr. 1, 2008) (hereinafter, referred to as Non-Patent Document 5), for example).
As described above, various search support techniques have been proposed heretofore.
However, the technique in Non-Patent Document 1 merely corrects a query according to an evaluation performed by the user on appropriateness of a document cluster, but does not correct a query by allowing a user to specify an appropriate keyword for a search in accordance with a user request. In addition, the technique disclosed in Non-Patent Document 2 performs query expansion on the basis of a search path generated using ontology information or the like, but does not perform query expansion on the basis of a search path including a keyword appropriate for a search in accordance with a user request. Accordingly, any one of the techniques does not resolve a problem that an appropriate keyword in accordance with a user request cannot be specified to perform a search.
Likewise, the techniques disclosed in Patent Document 1, and Non-Patent Documents 3 to 5 do not provide means for performing a search in accordance with a user request by allowing a user to specify a keyword appropriate for the search.